It is well known that many foods contain numerous health/wellness-promoting and disease-preventing/curing compounds (Schmidt et al., Nat. Chem. Biol., 3:360-366, 2007; Raskin et al., Curr. Pharm. Design, 10:3419-3429, 2004). Plants are a particularly rich source of such compounds. Unfortunately, the co-evolution of people and edible plants and the advance of modern agriculture have favored the reduction of beneficial, bioactive natural products in plant foods (Schmidt et al., Met. Clin. Exp., 57:S3-S9, 2008). Extensive plant breeding and selection has reduced the content of healthy ingredients, such as various antioxidants, polyphenols, bioflavonoids, glucosinolates, healthy fibers, fatty acids, vitamins, and minerals in most plant foods (Schmidt et al., supra). This reduction was caused by the need to maximize the caloric content, palatability, and digestibility of plant foods by directing plant metabolism to accumulating starches, sugars, oils, and/or major proteins in edible parts at the expense of losing bioactive secondary metabolites. As a result, many health promoting- and disease-fighting natural products and bioactives were reduced to levels where average daily consumption cannot produce measurable health benefits. To supply a beneficial amount of plant-derived bioactives, food plants are then extracted with solvents and sold in oral form as concentrated supplements.
Ion-exchange chromatography can be used for concentrating and isolating a great variety of compounds. It is based on specific electrostatic interactions between charges on the surface of solubilized compounds and solid ion exchangers (resins). As a result, some compounds bind to the ion exchange matrix, while others remain in the solution. Ion-exchangers and compounds should be in the same polarity range to effectively bind to each other. However, ion-exchange chromatography is very expensive because it uses synthetic resins and organic solvents to elute bound phytochemicals from resins. In addition to high cost, this method is often not allowed in food manufacturing and cannot be called “natural” or “organic.”